135 research outputs found
Energy flow in a hadronic cascade: Application to hadron calorimetry
The hadronic cascade description developed in an earlier paper is extended to
the response of an idealized fine-sampling hadron calorimeter. Calorimeter
response is largely determined by the transfer of energy from the
hadronic to the electromagnetic sector via production. Fluctuations in
this quantity produce the "constant term" in hadron calorimeter resolution. The
increase of its fractional mean, f_{\rm em}^0 = \vev{E_e}/E, with increasing
incident energy causes the energy dependence of the ratio in a
noncompensating calorimeter. The mean hadronic energy fraction, , was shown to scale very nearly as a power law in : , where GeV for pions, and . It
follows that , where electromagnetic and hadronic
energy deposits are detected with efficiencies and , respectively.
Fluctuations in these quantities, along with sampling fluctuations, are
incorporated to give an overall understanding of resolution, which is different
from the usual treatments in interesting ways. The conceptual framework is also
extended to the response to jets and the difference between and
response.Comment: This paper extends to HEP calorimetry the conceptual framework
developed in Gabriel, Groom Job, Mokhov, and Stevenson, "Energy dependence of
hadronic activity," NIM A 338 (1994) 336-34
Simplification of the DREAM collaboration's "Q/S method" in dual readout calorimetry analysis
The DREAM collaboration has introduced the "Q/S Method" for obtaining the
energy estimator from simultaneous Cherenkov and scintillator readouts of
individual hadronic events. We show that the algorithm is equivalent to an
elementary method
Muon stopping power and range tables 10 MeV-100 TeV
The mean stopping power for high-energy muons in matter can be described by −dE/dx = a(E) + b(E)E, where a(E) is the electronic stopping power and b(E) is the energy-scaled con-tribution from radiative processes—bremsstrahlung, pair production, and photonuclear interac-tions. a(E) and b(E) are both slowly-varying functions of the muon energy E where radiative effects are important. Tables of these stopping power contributions and continuous-slowing-down-approximation (CSDA) ranges (which neglect multiple scattering and range straggling) are given for a selection of elements, compounds, mixtures, and biological materials for incident kinetic en-ergies in the range 10 MeV to 100 TeV. Tables of the contributions to b(E) are given for the same materials
Towards a Roadmap for Advancing the Catalogue of the World’s Natural History Collections
Natural history collections are the foundations upon which all knowledge of natural history is constructed. Biological specimens are the best documentation of variation within each species, increasingly serve as curated sources for reference DNA, and are frequently our only evidence for historical species distribution. Collections represent an enormous multigenerational investment in research infrastructure for the biological sciences, but despite this importance most of the holdings of these institutions remain invisible on the Internet, inaccessible to taxonomists from other countries and hidden from computational biodiversity research.Although comprehensive digitisation of the complete holdings of each natural history collection is the long-term goal, this is an expensive and labor-intensive task and will not be completed in the near future for all collections. However, many benefits could quickly be achieved by publishing high-quality metadata on each collection to increase its visibility, provide the foundations for further digitisation and enable researchers to discover and communicate with collections of interest.This paper summarises the results from a consultation activity carried out in 2020 as part of the SYNTHESYS+ (Synthesys of Systematic Resources), “Developing implementation roadmaps for priority infrastructure areas as part of cooperative RI for biodiversity” project. This consultation was primed through an ideas paper, and introductory webinars and conducted as a facilitated two-week online multilingual discussion around 26 topics grouped under four broad headings (Users, Content, Technology and Governance). The results of these discussions are summarised here, along with the wider context of existing and planned initiatives
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Decadal variations in the global atmospheric land temperatures
Interannual to decadal variations in Earth global temperature estimates have often been identified with El Nino Southern Oscillation (ENSO) events. However, we show that variability on time scales of 2-15 years in mean annual global land surface temperature anomalies T-avg are more closely correlated with variability in sea surface temperatures in the North Atlantic. In particular, the cross-correlation of annually averaged values of T-avg with annual values of the Atlantic Multidecadal Oscillation (AMO) index is much stronger than that of T-avg with ENSO. The pattern of fluctuations in T-avg from 1950 to 2010 reflects true climate variability and is not an artifact of station sampling. A world map of temperature correlations shows that the association with AMO is broadly distributed and unidirectional. The effect of El Nino on temperature is locally stronger, but can be of either sign, leading to less impact on the global average. We identify one strong narrow spectral peak in the AMO at period 9.10.4 years and p value of 1.7% (confidence level, 98.3%). Variations in the flow of the Atlantic meridional overturning circulation may be responsible for some of the 2-15 year variability observed in global land temperatures.Keywords: global warming, decadal variations, Earth surface temperature, climate change, AM
Experimental Bounds on Masses and Fluxes of Nontopological Solitons
We have re-analyzed the results of various experiments which were not
originally interested as searches for the Q-ball or the Fermi-ball. Based on
these analyses, in addition to the available data on Q-balls, we obtained
rather stringent bounds on flux, mass and typical energy scale of Q-balls as
well as Fermi-balls. In case these nontopological solitons are the main
component of the dark matter of the Galaxy, we found that only such solitons
with very large quantum numbers are allowed. We also estimate how sensitive
future experiments will be in the search for Q-balls and Fermi-balls.Comment: 19 pages, 7 eps figures, RevTeX, psfig.st
Community engagement: The ‘last mile’ challenge for European research e-infrastructures
Europe is building its Open Science Cloud; a set of robust and interoperable e-infrastructures with the capacity to provide data and computational solutions through cloud-based services. The development and sustainable operation of such e-infrastructures are at the forefront of European funding priorities. The research community, however, is still reluctant to engage at the scale required to signal a Europe-wide change in the mode of operation of scientific practices. The striking differences in uptake rates between researchers from different scientific domains indicate that communities do not equally share the benefits of the above European investments. We highlight the need to support research communities in organically engaging with the European Open Science Cloud through the development of trustworthy and interoperable Virtual Research Environments. These domain-specific solutions can support communities in gradually bridging technical and socio-cultural gaps between traditional and open digital science practice, better diffusing the benefits of European e-infrastructures
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Improved Spatial Resolution in Thick, Fully-Depleted CCDs withEnhanced Red Sensitivity
The point spread function (PSF) is an important measure of spatial resolution in CCDs for point-like objects, since it affects image quality and spectroscopic resolution. We present new data and theoretical developments for lateral charge diffusion in thick, fully-depleted charge-coupled devices (CCDs) developed at Lawrence Berkeley National Laboratory (LBNL). Because they can be over-depleted, the LBNL devices have no field-free region and diffusion is controlled through the application of an external bias voltage. We give results for a 3512 x 3512 format, 10.5 {micro}m pixel back-illuminated p-channel CCD developed for the SuperNova/Acceleration Probe (SNAP), a proposed satellite-based experiment designed to study dark energy. The PSF was measured at substrate bias voltages between 3 V and 115 V. At a bias voltage of 115 V, we measure an rms diffusion of 3.7 {+-} 0.2 {micro}m. Lateral charge diffusion in LBNL CCDs will meet the SNAP requirements
In-reach specialist nursing teams for residential care homes : uptake of services, impact on care provision and cost-effectiveness
Background: A joint NHS-Local Authority initiative in England designed to provide a dedicated nursing and physiotherapy in-reach team (IRT) to four residential care homes has been evaluated.The IRT supported 131 residents and maintained 15 'virtual' beds for specialist nursing in these care homes.
Methods: Data captured prospectively (July 2005 to June 2007) included: numbers of referrals; reason for referral; outcome (e.g. admission to IRT bed, short-term IRT support); length of stay in IRT; prevented hospital admissions; early hospital discharges; avoided nursing home transfers; and detection of unrecognised illnesses. An economic analysis was undertaken.
Results: 733 referrals were made during the 2 years (range 0.5 to 13.0 per resident per annum)resulting in a total of 6,528 visits. Two thirds of referrals aimed at maintaining the resident's independence in the care home. According to expert panel assessment, 197 hospital admissions were averted over the period; 20 early discharges facilitated; and 28 resident transfers to a nursing home prevented. Detection of previously unrecognised illnesses accounted for a high number of visits. Investment in IRT equalled £44.38 per resident per week. Savings through reduced hospital admissions, early discharges, delayed transfers to nursing homes, and identification of previously
unrecognised illnesses are conservatively estimated to produce a final reduction in care cost of £6.33 per resident per week. A sensitivity analysis indicates this figure might range from a weekly overall saving of £36.90 per resident to a 'worst case' estimate of £2.70 extra expenditure per resident per week.
Evaluation early in implementation may underestimate some cost-saving activities and greater savings may emerge over a longer time period. Similarly, IRT costs may reduce over time due to the potential for refinement of team without major loss in effectiveness.
Conclusion: Introduction of a specialist nursing in-reach team for residential homes is at least cost neutral and, in all probability, cost saving. Further benefits include development of new skills in the care home workforce and enhanced quality of care. Residents are enabled to stay in familiar surroundings rather than unnecessarily spending time in hospital or being transferred to a higher
dependency nursing home setting
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